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95-687: Schuylkill Arsenal Railroad Bridge is a wrought iron , two-track, deck truss swing bridge across the Schuylkill River between the University City and Grays Ferry neighborhoods of Philadelphia, Pennsylvania . It was built in 1885–86 by the Pennsylvania Railroad . Today, its swing span has been fixed shut, and the electrical catenary de-energized. The bridge is named for the Schuylkill Arsenal , which operated from 1799 to 1926 near

190-520: A chisel . Heating generally takes place in a forge fueled by propane, natural gas, coal, charcoal, coke , or oil. Some modern blacksmiths may also employ an oxyacetylene or similar blowtorch for more localized heating. Induction heating methods are gaining popularity among modern blacksmiths. Color is important for indicating the temperature and workability of the metal. As iron heats to higher temperatures, it first glows red, then orange, yellow, and finally white. The ideal heat for most forging

285-449: A flux and give the material its unique, fibrous structure. The silicate filaments in the slag also protect the iron from corrosion and diminish the effect of fatigue caused by shock and vibration. Historically, a modest amount of wrought iron was refined into steel , which was used mainly to produce swords , cutlery , chisels , axes , and other edged tools, as well as springs and files. The demand for wrought iron reached its peak in

380-514: A bar, expelling slag in the process. During the Middle Ages , water-power was applied to the process, probably initially for powering bellows, and only later to hammers for forging the blooms. However, while it is certain that water-power was used, the details remain uncertain. That was the culmination of the direct process of ironmaking. It survived in Spain and southern France as Catalan Forges to

475-582: A carbon content of less than 0.008 wt% . Bar iron is a generic term sometimes used to distinguish it from cast iron. It is the equivalent of an ingot of cast metal, in a convenient form for handling, storage, shipping and further working into a finished product. The bars were the usual product of the finery forge , but not necessarily made by that process: Wrought iron is a form of commercial iron containing less than 0.10% of carbon, less than 0.25% of impurities total of sulfur, phosphorus, silicon and manganese, and less than 2% slag by weight. Wrought iron

570-401: A central center-pivot swing span. Wrought iron Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. It was given the name wrought because it was hammered, rolled, or otherwise worked while hot enough to expel molten slag. The modern functional equivalent of wrought iron

665-417: A chisel, since it is lengthened by drawing it would also tend to spread in width. A smith would therefore frequently turn the chisel-to-be on its side and hammer it back down—upsetting it—to check the spread and keep the metal at the correct width. Or, if a smith needed to put a 90-degree bend in a bar and wanted a sharp corner on the outside of the bend, they would begin by hammering an unsupported end to make

760-470: A final product. Sometimes European ironworks would skip the shingling process completely and roll the puddle balls. The only drawback to that is that the edges of the rough bars were not as well compressed. When the rough bar was reheated, the edges might separate and be lost into the furnace. The bloom was passed through rollers and to produce bars. The bars of wrought iron were of poor quality, called muck bars or puddle bars. To improve their quality,

855-463: A high silky luster and fibrous appearance. Wrought iron lacks the carbon content necessary for hardening through heat treatment , but in areas where steel was uncommon or unknown, tools were sometimes cold-worked (hence cold iron ) to harden them. An advantage of its low carbon content is its excellent weldability. Furthermore, sheet wrought iron cannot bend as much as steel sheet metal when cold worked. Wrought iron can be melted and cast; however,

950-434: A low scale to supply the steel to the artisan swordmakers. Osmond iron consisted of balls of wrought iron, produced by melting pig iron and catching the droplets on a staff, which was spun in front of a blast of air so as to expose as much of it as possible to the air and oxidise its carbon content. The resultant ball was often forged into bar iron in a hammer mill. In the 15th century, the blast furnace spread into what

1045-449: A lower melting point than iron or steel. Cast and especially pig iron have excess slag which must be at least partially removed to produce quality wrought iron. At foundries it was common to blend scrap wrought iron with cast iron to improve the physical properties of castings. For several years after the introduction of Bessemer and open hearth steel, there were different opinions as to what differentiated iron from steel; some believed it

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1140-589: A number of patented processes for that, which are referred to today as potting and stamping . The earliest were developed by John Wood of Wednesbury and his brother Charles Wood of Low Mill at Egremont , patented in 1763. Another was developed for the Coalbrookdale Company by the Cranage brothers . Another important one was that of John Wright and Joseph Jesson of West Bromwich . A number of processes for making wrought iron without charcoal were devised as

1235-420: A point results. Drawing can be accomplished with a variety of tools and methods. Two typical methods using only hammer and anvil would be hammering on the anvil horn, and hammering on the anvil face using the cross peen of a hammer. Another method for drawing is to use a tool called a fuller , or the peen of the hammer, to hasten the drawing out of a thick piece of metal. (The technique is called fullering from

1330-410: A process for manufacturing wrought iron quickly and economically. It involved taking molten steel from a Bessemer converter and pouring it into cooler liquid slag. The temperature of the steel is about 1500 °C and the liquid slag is maintained at approximately 1200 °C. The molten steel contains a large amount of dissolved gases so when the liquid steel hit the cooler surfaces of the liquid slag

1425-422: A process in which the blacksmith permanently joins two pieces of iron, or a piece of iron and a piece of steel, by heating them nearly to a white heat and hammering them together. Forge welding is more difficult with modern mild steel, because it welds in a narrower temperature band. The fibrous nature of wrought iron required knowledge and skill to properly form any tool which would be subject to stress. Modern steel

1520-410: A refinery where raw coal was used to remove silicon and convert carbon within the raw material, found in the form of graphite, to a combination with iron called cementite. In the fully developed process (of Hall), this metal was placed into the hearth of the puddling furnace where it was melted. The hearth was lined with oxidizing agents such as haematite and iron oxide. The mixture was subjected to

1615-481: A single hearth for all stages. The introduction of coke for use in the blast furnace by Abraham Darby in 1709 (or perhaps others a little earlier) initially had little effect on wrought iron production. Only in the 1750s was coke pig iron used on any significant scale as the feedstock of finery forges. However, charcoal continued to be the fuel for the finery. From the late 1750s, ironmasters began to develop processes for making bar iron without charcoal. There were

1710-498: A smith makes sure the fire is a reducing fire: a fire where, at the heart, there is a great deal of heat and very little oxygen. The smith also carefully shapes mating faces so that as they come together foreign material squeezes out as the metal is joined. To clean the faces, protect them from oxidation, and provide a medium to carry foreign material out of the weld, the smith sometimes uses flux—typically powdered borax, silica sand, or both. The smith first cleans parts to be joined with

1805-412: A strong current of air and stirred with long bars, called puddling bars or rabbles, through working doors. The air, the stirring, and the "boiling" action of the metal helped the oxidizing agents to oxidize the impurities and carbon out of the pig iron. As the impurities oxidize, they formed a molten slag or drifted off as gas, while the remaining iron solidified into spongy wrought iron that floated to

1900-418: A wire brush, then puts them in the fire to heat. With a mix of drawing and upsetting the smith shapes the faces so that when finally brought together, the center of the weld connects first and the connection spreads outward under the hammer blows, pushing out the flux (if used) and foreign material. The dressed metal goes back in the fire, is brought near to welding heat, removed from the fire, and brushed. Flux

1995-424: Is redshort or hot short if it contains sulfur in excess quantity. It has sufficient tenacity when cold, but cracks when bent or finished at a red heat. Hot short iron was considered unmarketable. Cold short iron, also known as coldshear , colshire , contains excessive phosphorus. It is very brittle when cold and cracks if bent. It may, however, be worked at high temperature. Historically, coldshort iron

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2090-413: Is mild steel , also called low-carbon steel. Neither wrought iron nor mild steel contain enough carbon to be hardened by heating and quenching. Wrought iron is highly refined, with a small amount of silicate slag forged out into fibers. It comprises around 99.4% iron by mass. The presence of slag can be beneficial for blacksmithing operations, such as forge welding, since the silicate inclusions act as

2185-454: Is a heroic blacksmith in Germanic mythology. The Poetic Edda states that he forged beautiful gold rings set with wonderful gems. He was captured by king Níðuðr , who cruelly hamstrung him and imprisoned him on an island. Völundr eventually had his revenge by killing Níðuðr's sons and fashioning goblets from their skulls, jewels from their eyes and a brooch from their teeth. He then raped

2280-414: Is a more important measure of the quality of wrought iron. In tensile testing, the best irons are able to undergo considerable elongation before failure. Higher tensile wrought iron is brittle. Because of the large number of boiler explosions on steamboats in the early 1800s, the U.S. Congress passed legislation in 1830 which approved funds for correcting the problem. The treasury awarded a $ 1500 contract to

2375-513: Is an archaic past participle of the verb "to work", and so "wrought iron" literally means "worked iron". Wrought iron is a general term for the commodity, but is also used more specifically for finished iron goods, as manufactured by a blacksmith . It was used in that narrower sense in British Customs records, such manufactured iron was subject to a higher rate of duty than what might be called "unwrought" iron. Cast iron , unlike wrought iron,

2470-416: Is an assistant (frequently an apprentice ) whose job is to swing a large sledgehammer in heavy forging operations, as directed by the blacksmith. In practice, the blacksmith holds the hot iron at the anvil (with tongs) in one hand, and indicates where to strike the iron by tapping it with a small hammer in the other hand. The striker then delivers a heavy blow to the indicated spot with a sledgehammer. During

2565-435: Is brittle and cannot be worked either hot or cold. In the 17th, 18th, and 19th centuries, wrought iron went by a wide variety of terms according to its form, origin, or quality. While the bloomery process produced wrought iron directly from ore, cast iron or pig iron were the starting materials used in the finery forge and puddling furnace . Pig iron and cast iron have higher carbon content than wrought iron, but have

2660-491: Is deceptive. Most of the manganese, sulfur, phosphorus, and silicon in the wrought iron are incorporated into the slag fibers, making wrought iron purer than plain carbon steel. Amongst its other properties, wrought iron becomes soft at red heat and can be easily forged and forge welded . It can be used to form temporary magnets , but it cannot be magnetized permanently, and is ductile , malleable , and tough . For most purposes, ductility rather than tensile strength

2755-407: Is no longer manufactured commercially. Wrought iron was originally produced by a variety of smelting processes, all described today as "bloomeries". Different forms of bloomery were used at different places and times. The bloomery was charged with charcoal and iron ore and then lit. Air was blown in through a tuyere to heat the bloomery to a temperature somewhat below the melting point of iron. In

2850-450: Is no longer produced on a commercial scale. Many products described as wrought iron, such as guard rails , garden furniture , and gates are made of mild steel. They are described as "wrought iron" only because they have been made to resemble objects which in the past were wrought (worked) by hand by a blacksmith (although many decorative iron objects, including fences and gates, were often cast rather than wrought). The word "wrought"

2945-468: Is not smelted and cannot come from this process) " or "mild steel." The terms are never interchangeable. In preindustrial times, the material of choice for blacksmiths was wrought iron. This iron had a very low carbon content, and also included up to 5% of glassy iron silicate slag in the form of numerous very fine stringers. This slag content made the iron very tough, gave it considerable resistance to rusting, and allowed it to be more easily "forge welded,"

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3040-615: Is now Belgium where it was improved. From there, it spread via the Pays de Bray on the boundary of Normandy and then to the Weald in England. With it, the finery forge spread. Those remelted the pig iron and (in effect) burnt out the carbon, producing a bloom, which was then forged into bar iron. If rod iron was required, a slitting mill was used. The finery process existed in two slightly different forms. In Great Britain, France, and parts of Sweden, only

3135-422: Is over 2%, the metal is called cast iron , because it has a relatively low melting point and is easily cast. It is quite brittle, however, and cannot be forged so therefore not used for blacksmithing. If the carbon content is between 0.25% and 2%, the resulting metal is tool steel , which can be heat treated as discussed above. When the carbon content is below 0.25%, the metal is either " wrought iron (wrought iron

3230-505: Is produced using either the blast furnace or arc furnaces. Wrought iron was produced by a labor-intensive process called puddling , so this material is now a difficult-to-find specialty product. Modern blacksmiths generally substitute mild steel for making objects traditionally of wrought iron. Sometimes they use electrolytic-process pure iron. Many blacksmiths also incorporate materials such as bronze , copper , or brass in artistic products. Aluminum and titanium may also be forged by

3325-437: Is sometimes applied, which prevents oxygen from reaching and burning the metal during forging, and it is returned to the fire. The smith now watches carefully to avoid overheating the metal. There is some challenge to this because, to see the color of the metal, the smith must remove it from the fire—exposing it to air, which can rapidly oxidize it. So the smith might probe into the fire with a bit of steel wire, prodding lightly at

3420-400: Is sufficiently corrosion-resistant that artifacts of bronze may last thousands of years relatively unscathed. Accordingly, museums frequently preserve more examples of Bronze Age metal-work than examples of artifacts from the much younger Iron Age . Buried iron artifacts may completely rust away in less than 100 years. Examples of ancient iron work still extant are very much the exception to

3515-500: Is the blacksmith of the devas . The earliest references of Tvastar can be found in the Rigveda . Hephaestus (Latin: Vulcan ) was the blacksmith of the gods in Greek and Roman mythology . A supremely skilled artisan whose forge was a volcano, he constructed most of the weapons of the gods, as well as beautiful assistants for his smithy and a metal fishing-net of astonishing intricacy. He

3610-591: Is the bright yellow-orange color that indicates forging heat . Because they must be able to see the glowing color of the metal, some blacksmiths work in dim, low-light conditions, but most work in well-lit conditions. The key is to have consistent lighting, but not too bright. Direct sunlight obscures the colors. The techniques of smithing can be roughly divided into forging (sometimes called "sculpting"), welding, heat-treating, and finishing. Forging —the process smiths use to shape metal by hammering—differs from machining in that forging does not remove material. Instead,

3705-472: The Industrial Revolution began during the latter half of the 18th century. The most successful of those was puddling, using a puddling furnace (a variety of the reverberatory furnace ), which was invented by Henry Cort in 1784. It was later improved by others including Joseph Hall , who was the first to add iron oxide to the charge. In that type of furnace, the metal does not come into contact with

3800-595: The Walloon process was used. That employed two different hearths, a finery hearth for finishing the iron and a chafery hearth for reheating it in the course of drawing the bloom out into a bar. The finery always burnt charcoal, but the chafery could be fired with mineral coal , since its impurities would not harm the iron when it was in the solid state. On the other hand, the German process, used in Germany, Russia, and most of Sweden used

3895-517: The bloomery ever being used in China. The fining process involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation . Wagner writes that in addition to the Han dynasty hearths believed to be fining hearths, there is also pictorial evidence of the fining hearth from a Shandong tomb mural dated 1st to 2nd century AD, as well as a hint of written evidence in

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3990-413: The finery forge at least by the 2nd century BC, the earliest specimens of cast and pig iron fined into wrought iron and steel found at the early Han dynasty site at Tieshengguo. Pigott speculates that the finery forge existed in the previous Warring States period (403–221 BC), due to the fact that there are wrought iron items from China dating to that period and there is no documented evidence of

4085-443: The metal , using tools to hammer, bend, and cut (cf. tinsmith ). Blacksmiths produce objects such as gates, grilles, railings, light fixtures, furniture, sculpture, tools, agricultural implements, decorative and religious items, cooking utensils, and weapons. There was a historical distinction between the heavy work of the blacksmith and the more delicate operations of a whitesmith , who usually worked in gold , silver , pewter , or

4180-778: The 1860s, being in high demand for ironclad warships and railway use. However, as properties such as brittleness of mild steel improved with better ferrous metallurgy and as steel became less costly to make thanks to the Bessemer process and the Siemens–Martin process , the use of wrought iron declined. Many items, before they came to be made of mild steel , were produced from wrought iron, including rivets , nails , wire , chains , rails , railway couplings , water and steam pipes , nuts , bolts , horseshoes , handrails , wagon tires, straps for timber roof trusses , and ornamental ironwork , among many other things. Wrought iron

4275-680: The 1960s, the price of steel production was dropping due to recycling, and even using the Aston process, wrought iron production was labor-intensive. It has been estimated that the production of wrought iron is approximately twice as expensive as that of low-carbon steel. In the United States, the last plant closed in 1969. The last in the world was the Atlas Forge of Thomas Walmsley and Sons in Bolton , Great Britain, which closed in 1973. Its 1860s-era equipment

4370-412: The 20th century and into the 21st century, this role has become increasingly unnecessary and automated through the use of trip hammers or reciprocating power hammers. When iron ore is smelted into usable metal, a certain amount of carbon is usually alloyed with the iron. (Charcoal is almost pure carbon.) The amount of carbon significantly affects the properties of the metal. If the carbon content

4465-418: The 4th century AD Daoist text Taiping Jing . Wrought iron has been used for many centuries, and is the "iron" that is referred to throughout Western history. The other form of iron, cast iron , was in use in China since ancient times but was not introduced into Western Europe until the 15th century; even then, due to its brittleness, it could be used for only a limited number of purposes. Throughout much of

4560-559: The Franklin Institute to conduct a study. As part of the study, Walter R. Johnson and Benjamin Reeves conducted strength tests on boiler iron using a tester they had built in 1832 based on a design by Lagerhjelm in Sweden. Because of misunderstandings about tensile strength and ductility, their work did little to reduce failures. The importance of ductility was recognized by some very early in

4655-536: The Middle Ages, iron was produced by the direct reduction of ore in manually operated bloomeries , although water power had begun to be employed by 1104. The raw material produced by all indirect processes is pig iron. It has a high carbon content and as a consequence, it is brittle and cannot be used to make hardware. The osmond process was the first of the indirect processes, developed by 1203, but bloomery production continued in many places. The process depended on

4750-456: The appropriately shaped part of the anvil. Some metals are "hot short", meaning they lose their tensile strength when heated. They become like Plasticine : although they may still be manipulated by squeezing, an attempt to stretch them, even by bending or twisting, is likely to have them crack and break apart. This is a problem for some blade-making steels, which must be worked carefully to avoid developing hidden cracks that would cause failure in

4845-451: The bars were cut up, piled and tied together by wires, a process known as faggoting or piling. They were then reheated to a welding state, forge welded, and rolled again into bars. The process could be repeated several times to produce wrought iron of desired quality. Wrought iron that has been rolled multiple times is called merchant bar or merchant iron. The advantage of puddling was that it used coal, not charcoal as fuel. However, that

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4940-518: The black firescale , a layer of oxides that forms on the surface of the metal during heating. The origin of smith is the Old English word smið meaning "blacksmith", originating from the Proto-Germanic *smiþaz meaning "skilled worker". Blacksmiths work by heating pieces of wrought iron or steel until the metal becomes soft enough for shaping with hand tools, such as a hammer, an anvil and

5035-550: The blacksmith's process. Bronze is an alloy of copper and tin , while brass is an alloy of copper and zinc . Each material responds differently under the hammer and must be separately studied by the blacksmith. Steel with less than 0.6% carbon content cannot be hardened enough by simple heat-treatment to make useful hardened-steel tools. Hence, in what follows, wrought-iron, low-carbon-steel, and other soft unhardenable iron varieties are referred to indiscriminately as just iron . In Hindu mythology, Tvastar also known as Vishvakarma

5130-635: The bridge's eastern approaches. Its western approach runs past the University of Pennsylvania 's Meiklejohn Stadium . In January 2014, a CSX train carrying crude oil derailed on the bridge. The 1886 bridge replaced the original Arsenal Bridge, which was built by the Pennsylvania Railroad in 1861 and put in operation on January 27, 1862, as part of the Delaware Extension . It carried a single track over three wrought-iron spans on stone piers and

5225-582: The copper used by the Mediterranean World came from the island of Cyprus . Most of the tin came from the Cornwall region of the island of Great Britain , transported by sea-borne Phoenician and Greek traders. Copper and bronze cannot be hardened by heat-treatment, they can only be hardened by cold working . To accomplish this, a piece of bronze is lightly hammered for a long period of time. The localized stress-cycling causes work hardening by changing

5320-413: The course of the smelt, slag would melt and run out, and carbon monoxide from the charcoal would reduce the ore to iron, which formed a spongy mass (called a "bloom") containing iron and also molten silicate minerals (slag) from the ore. The iron remained in the solid state. If the bloomery were allowed to become hot enough to melt the iron, carbon would dissolve into it and form pig or cast iron, but that

5415-465: The curve had been properly shaped. In the primary operation was the bend, but the drawing and upsetting are done to refine the shape. Welding is the joining of the same or similar kind of metal. A modern blacksmith has a range of options and tools to accomplish this. The basic types of welding commonly employed in a modern workshop include traditional forge welding as well as modern methods, including oxyacetylene and arc welding . In forge welding,

5510-427: The curved bend. Then, to "fatten up" the outside radius of the bend, one or both arms of the bend would need to be pushed back to fill the outer radius of the curve. So they would hammer the ends of the stock down into the bend, 'upsetting' it at the point of the bend. They would then dress the bend by drawing the sides of the bend to keep the correct thickness. The hammering would continue—upsetting and then drawing—until

5605-580: The development of the blast furnace, of which medieval examples have been discovered at Lapphyttan , Sweden and in Germany . The bloomery and osmond processes were gradually replaced from the 15th century by finery processes, of which there were two versions, the German and Walloon. They were in turn replaced from the late 18th century by puddling , with certain variants such as the Swedish Lancashire process . Those, too, are now obsolete, and wrought iron

5700-495: The development of tube boilers, evidenced by Thurston's comment: If made of such good iron as the makers claimed to have put into them "which worked like lead," they would, as also claimed, when ruptured, open by tearing, and discharge their contents without producing the usual disastrous consequences of a boiler explosion. Blacksmith A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel , but sometimes from other metals , by forging

5795-473: The finishing steps of fine steel. The place where a blacksmith works is variously called a smithy , a forge , or a blacksmith's shop . While there are many professions who work with metal, such as farriers , wheelwrights , and armorers , in former times the blacksmith had a general knowledge of how to make and repair many things, from the most complex of weapons and armor to simple things like nails or lengths of chain. The "black" in "blacksmith" refers to

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5890-481: The flat face of the hammer. Heating iron to a "forging heat" allows bending as if it were a soft, ductile metal, like copper or silver. Bending can be done with the hammer over the horn or edge of the anvil or by inserting a bending fork into the hardy hole (the square hole in the top of the anvil), placing the work piece between the tines of the fork, and bending the material to the desired angle. Bends can be dressed and tightened, or widened, by hammering them over

5985-432: The fuel, and so is not contaminated by its impurities. The heat of the combustion products passes over the surface of the puddle and the roof of the furnace reverberates (reflects) the heat onto the metal puddle on the fire bridge of the furnace. Unless the raw material used is white cast iron, the pig iron or other raw product of the puddling first had to be refined into refined iron , or finers metal. That would be done in

6080-427: The future. Though rarely hand-worked, titanium is notably hot short. Even such common smithing processes as decoratively twisting a bar are impossible with it. Upsetting is the process of making metal thicker in one dimension through shortening in the other. One form is to heat the end of a rod and then hammer on it as one would drive a nail: the rod gets shorter, and the hot part widens. An alternative to hammering on

6175-401: The gases were liberated. The molten steel then froze to yield a spongy mass having a temperature of about 1370 °C. The spongy mass would then be finished by being shingled and rolled as described under puddling (above). Three to four tons could be converted per batch with the method. Steel began to replace iron for railroad rails as soon as the Bessemer process for its manufacture

6270-480: The god of blacksmiths, warriors, hunters and others who work with iron is one of the pantheon of Orisha traditionally worshipped by the Yoruba people of Nigeria . Gold , silver , and copper all occur in nature in their native states , as reasonably pure metals – humans probably worked these metals first. These metals are all quite malleable , and humans' initial development of hammering techniques

6365-563: The hero known to the Ossetians as Kurdalægon and the Circassians as Tlepsh is a blacksmith and skilled craftsman whose exploits exhibit shamanic features, sometimes bearing comparison to those of the Scandinavian deity Odin . One of his greatest feats is acting as a type of male midwife to the hero Xamyc , who has been made the carrier of the embryo of his son Batraz by his dying wife

6460-474: The hot end is to place the hot end on the anvil and hammer on the cold end. Punching may be done to create a decorative pattern, or to make a hole. For example, in preparation for making a hammerhead, a smith would punch a hole in a heavy bar or rod for the hammer handle. Punching is not limited to depressions and holes. It also includes cutting, slitting, and drifting—all done with a chisel. The five basic forging processes are often combined to produce and refine

6555-430: The iron. The included slag in wrought iron also imparts corrosion resistance. Antique music wire , manufactured at a time when mass-produced carbon-steels were available, was found to have low carbon and high phosphorus; iron with high phosphorus content, normally causing brittleness when worked cold, was easily drawn into music wires. Although at the time phosphorus was not an easily identified component of iron, it

6650-554: The king's daughter, after drugging her with strong beer, and escaped, laughing, on wings of his own making, boasting that he had fathered a child upon her. Seppo Ilmarinen , the Eternal Hammerer, blacksmith and inventor in the Kalevala , is an archetypal artificer from Finnish mythology. Tubal-Cain is mentioned in the book of Genesis of the Torah as the original smith. Ogun ,

6745-454: The mating faces. When the end of the wire sticks on to the metal, it is at the right temperature (a small weld forms where the wire touches the mating face, so it sticks). The smith commonly places the metal in the fire so he can see it without letting surrounding air contact the surface. (Note that smiths don't always use flux, especially in the UK.) Now the smith moves with rapid purpose, quickly taking

6840-455: The metal by reducing one or both of the other two dimensions. As the depth is reduced, or the width narrowed, the piece is lengthened or "drawn out." As an example of drawing, a smith making a chisel might flatten a square bar of steel, lengthening the metal, reducing its depth but keeping its width consistent. Drawing does not have to be uniform. A taper can result as in making a wedge or a woodworking chisel blade. If tapered in two dimensions,

6935-433: The metal from the fire to the anvil and bringing the mating faces together. A few light hammer taps bring the mating faces into complete contact and squeeze out the flux—and finally, the smith returns the work to the fire. The weld begins with the taps, but often the joint is weak and incomplete, so the smith reheats the joint to welding temperature and works the weld with light blows to "set" the weld and finally to dress it to

7030-504: The mid 19th century, in Austria as the stuckofen to 1775, and near Garstang in England until about 1770; it was still in use with hot blast in New York in the 1880s. In Japan the last of the old tatara bloomeries used in production of traditional tamahagane steel, mainly used in swordmaking, was extinguished only in 1925, though in the late 20th century the production resumed on

7125-617: The norm. Concurrent with the advent of alphabetic characters in the Iron Age , humans became aware of the metal iron . However, in earlier ages, iron's qualities, in contrast to those of bronze, were not generally understood. Iron artifacts , composed of meteoric iron , have the chemical composition containing up to 40% nickel . As this source of this iron is extremely rare and fortuitous, little development of smithing skills peculiar to iron can be assumed to have occurred. That we still possess any such artifacts of meteoric iron may be ascribed to

7220-436: The pieces to join are heated to what is generally referred to as welding heat . For mild steel most smiths judge this temperature by color: the metal glows an intense yellow or white. At this temperature the steel is near molten. Any foreign material in the weld, such as the oxides or "scale" that typically form in the fire, can weaken it and cause it to fail. Thus the mating surfaces to be joined must be kept clean. To this end

7315-666: The product is no longer wrought iron, since the slag stringers characteristic of wrought iron disappear on melting, so the product resembles impure, cast, Bessemer steel. There is no engineering advantage to melting and casting wrought iron, as compared to using cast iron or steel, both of which are cheaper. Due to the variations in iron ore origin and iron manufacture, wrought iron can be inferior or superior in corrosion resistance, compared to other iron alloys. There are many mechanisms behind its corrosion resistance. Chilton and Evans found that nickel enrichment bands reduce corrosion. They also found that in puddled, forged, and piled iron,

7410-531: The same manner as mild steel, but the presence of oxide or inclusions will give defective results. The material has a rough surface, so it can hold platings and coatings better than smooth steel. For instance, a galvanic zinc finish applied to wrought iron is approximately 25–40% thicker than the same finish on steel. In Table 1, the chemical composition of wrought iron is compared to that of pig iron and carbon steel . Although it appears that wrought iron and plain carbon steel have similar chemical compositions, that

7505-420: The shape. Depending on the intended use of the piece, a blacksmith may finish it in a number of ways: A range of treatments and finishes can inhibit oxidation and enhance or change the appearance of the piece. An experienced smith selects the finish based on the metal and on the intended use of the item. Finishes include (among others): paint, varnish, bluing , browning , oil, and wax. A blacksmith's striker

7600-418: The shapes necessary for finished products. For example, to fashion a cross-peen hammer head, a smith would start with a bar roughly the diameter of the hammer face: the handle hole would be punched and drifted (widened by inserting or passing a larger tool through it), the head would be cut (punched, but with a wedge), the peen would be drawn to a wedge, and the face would be dressed by upsetting. As with making

7695-454: The size and shape of the metal's crystals . The hardened bronze can then be ground to sharpen it to make edged tools. Clocksmiths as recently as the 19th century used work hardening techniques to harden the teeth of brass gears and ratchets . Tapping on just the teeth produced harder teeth, with superior wear-resistance. By contrast, the rest of the gear was left in a softer and tougher state, more capable of resisting cracking. Bronze

7790-429: The smith hammers the iron into shape. Even punching and cutting operations (except when trimming waste) by smiths usually re-arrange metal around the hole, rather than drilling it out as swarf . Forging uses seven basic operations or techniques: These operations generally require at least a hammer and anvil , but smiths also use other tools and techniques to accommodate odd-sized or repetitive jobs. Drawing lengthens

7885-478: The tool.) Fullering consists of hammering a series of indentations with corresponding ridges, perpendicular to the long section of the piece being drawn. The resulting effect looks somewhat like waves along the top of the piece. Then the smith turns the hammer over to use the flat face to hammer the tops of the ridges down level with the bottoms of the indentations. This forces the metal to grow in length (and width if left unchecked) much faster than just hammering with

7980-465: The top of the puddle and was fished out of the melt as puddle balls, using puddle bars. There was still some slag left in the puddle balls, so while they were still hot they would be shingled to remove the remaining slag and cinder. That was achieved by forging the balls under a hammer, or by squeezing the bloom in a machine. The material obtained at the end of shingling is known as bloom. The blooms are not useful in that form, so they were rolled into

8075-487: The water-sprite Lady Isp, who spits it between his shoulder blades, where it forms a womb-like cyst. Kurdalaegon prepares a type of tower or scaffold above a quenching bath for Xamyc, and, when the time is right, lances the cyst to liberate the infant hero Batraz as a newborn babe of white-hot steel , whom Kurdalægon then quenches like a newly forged sword. The Anglo-Saxon Wayland Smith , known in Old Norse as Völundr ,

8170-560: The working-over of the metal spread out copper, nickel, and tin impurities that produce electrochemical conditions that slow down corrosion. The slag inclusions have been shown to disperse corrosion to an even film, enabling the iron to resist pitting. Another study has shown that slag inclusions are pathways to corrosion. Other studies show that sulfur in the wrought iron decreases corrosion resistance, while phosphorus increases corrosion resistance. Chloride ions also decrease wrought iron's corrosion resistance. Wrought iron may be welded in

8265-479: Was adopted (1865 on). Iron remained dominant for structural applications until the 1880s, because of problems with brittle steel, caused by introduced nitrogen, high carbon, excess phosphorus, or excessive temperature during or too-rapid rolling. By 1890 steel had largely replaced iron for structural applications. Sheet iron (Armco 99.97% pure iron) had good properties for use in appliances, being well-suited for enamelling and welding, and being rust-resistant. In

8360-484: Was considered sufficient for nails . Phosphorus is not necessarily detrimental to iron. Ancient Near Eastern smiths did not add lime to their furnaces. The absence of calcium oxide in the slag, and the deliberate use of wood with high phosphorus content during the smelting, induces a higher phosphorus content (typically <0.3%) than in modern iron (<0.02–0.03%). Analysis of the Iron Pillar of Delhi gives 0.11% in

8455-515: Was hypothesized that the type of iron had been rejected for conversion to steel but excelled when tested for drawing ability. During the Han dynasty (202 BC – 220 AD), new iron smelting processes led to the manufacture of new wrought iron implements for use in agriculture, such as the multi-tube seed drill and iron plough . In addition to accidental lumps of low-carbon wrought iron produced by excessive injected air in ancient Chinese cupola furnaces . The ancient Chinese created wrought iron by using

8550-471: Was moved to the Blists Hill site of Ironbridge Gorge Museum for preservation. Some wrought iron is still being produced for heritage restoration purposes, but only by recycling scrap. The slag inclusions, or stringers , in wrought iron give it properties not found in other forms of ferrous metal. There are approximately 250,000 inclusions per square inch. A fresh fracture shows a clear bluish color with

8645-445: Was not the intention. However, the design of a bloomery made it difficult to reach the melting point of iron and also prevented the concentration of carbon monoxide from becoming high. After smelting was complete, the bloom was removed, and the process could then be started again. It was thus a batch process, rather than a continuous one such as a blast furnace. The bloom had to be forged mechanically to consolidate it and shape it into

8740-528: Was of little advantage in Sweden, which lacked coal. Gustaf Ekman observed charcoal fineries at Ulverston , which were quite different from any in Sweden. After his return to Sweden in the 1830s, he experimented and developed a process similar to puddling but used firewood and charcoal, which was widely adopted in the Bergslagen in the following decades. In 1925, James Aston of the United States developed

8835-473: Was the chemical composition and others that it was whether the iron heated sufficiently to melt and "fuse". Fusion eventually became generally accepted as relatively more important than composition below a given low carbon concentration. Another difference is that steel can be hardened by heat treating . Historically, wrought iron was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require

8930-612: Was the god of metalworking, fire, and craftsmen. In Celtic mythology , the role of Smith is held by eponymous (their names do mean 'smith') characters : Goibhniu (Irish myths of the Tuatha Dé Danann cycle) or Gofannon (Welsh myths/ the Mabinogion ). Brigid or Brigit, an Irish goddess , is sometimes described as the patroness of blacksmiths. In the Nart mythology of the Caucasus

9025-620: Was undoubtedly applied to these metals. During the Chalcolithic era and the Bronze Age , humans in the Mideast learned how to smelt , melt , cast , rivet , and (to a limited extent) forge copper and bronze. Bronze is an alloy of copper and approximately 10% to 20% Tin . Bronze is superior to just copper, by being harder, being more resistant to corrosion, and by having a lower melting point (thereby requiring less fuel to melt and cast). Much of

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